An audition website is a web site that aggregates audition information and delivers this information via the World Wide Web. There are hundreds of companies that operate acting, modeling, and dancing audition websites. Originally, only talent agents were able to provide actors, models, dancers and other performers with audition information. This meant that only performers that were represented by Talent Agents could go on auditions. Today, both open auditions and private auditions can be found on reliable audition websites. Talented performers can browse the World Wide Web and find many different audition websites. The primary organization of professional screen and theater casting in the United States is the Casting Society of America (CSA). Membership to the CSA is optional.